AnandTech heard the Radeon X1300 and X1600 won't need a master card to enable CrossFire as ATI will launch a new driver later this month that will enable CrossFire over the PXI Express bus for these two video GPUs.
I guess this driver will be Catalyst 5.11.
Low end NVIDIA cards can already run in SLI mode with out any additional support. Even on high end cards, the SLI bridge can be removed with a performance hit. These bridge-less, cable-less Radeons will represent the purest vision of a multi-GPU configuration. Rather than purchase a BBA (Built By ATI) master card, any AIB or BBA Radeon X1600 will work together in Crossfire mode. AIB partners could not confirm as to whether separate graphic card families would also work together in Crossfire mode.